Arrangement for the equal distribution of the throughput of a mixture of solids and fluids in a vertical pipe



y 30, 1961 B. TRENTINI EI'AL 2,986,343

ARRANGEMENT FOR THE EQUAL DISTRIBUTION OF THE THROUGHPUT OF A MIXTURE OFSOLIDS AND FLUIDS IN A VERTICAL PIPE Filed Feb. 19, 1958 Fig.1

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United States Patent 1 2,986,343 ARRANGEMENT FOR THE EQUAL DISTRIBUTIONOF THE THROUGHPUT OF A MIXTURE 0F SOLIDS AND FLUIDS IN A VERTICAL PIPEBernard Trentini, St. Germain-en-Laye, and Georges Cohen de Lara,Grenoble, France, assignors to Inshtut de Recherches de la Siderurgie,Saint Germain-en- Laye, a professional institution of France, andSocrete Grenobloise dEtudes et dApplications Hyorauhques, Socit Anonyme,Grenoble, France, a French com- P y Filed Feb. '19, 1958, Ser. No.716,188 Claims priority, application France Feb. 25, 1957 4 Claims. (Cl.239468) It is often desired to distribute uniformly a compound solid andfluid throughput flowing through a pipe system, between several tuyeresconnected with a single feed circuit.

Thus, in the case of the blowing of pulverulent materials through-tuyeres into a metallurgical container, such as a ladle, diflicultiesare met when it is attempted to obtain a uniform distribution of saidpulverulent material in the different tuyeres, which may lead to aclogging and reduces the grade of the stirring. It is a well-known factthat in a horizontal flow of a fluid carrying solid particles along withit, there exists a gradient of the concentrations in each transversecross-section of the pipe, the higher concentrations being found in thevicinity of the lower generating lines and the lower concentrations inthe vicinity of the upper generating lines. It is furthermore known thata vertical pipe of a suflicient length allows obtaining a suificientlyuniform distribution of the solid particles in a carrier fluid.

Unfortunately, this latter arrangement is not always applicable forobvious reasons of bulk and of location and it is often impossible toprovide rectilinear sections the length of which is suflicient forobtaining a uniform distribution of the solid and fluid throughputs.Furthermore, it should be observed that the bend which is re quired forconnecting the horizontal section of a conveyor with a vertical sectionsuch as that referred to, has a very marked action on the distributionof the solid particles in the vertical feed section.

The main object of our invention is to solve these difliculties throughan arrangement which allows obtaining a uniform distribution of thesolid and fluid throughputs in a pipe system whenever this distributionwould be otherwise imperfect as a consequence of the manner of feedingthe solid and fluid material, or its uniformity has been destroyedduring horizontal flow under the action of gravity and friction.

Another object of our invention is to provide an arrangement forobtaining the uniform distribution of a throughput of a mixture ofsolids and fluids inside a vertical pipe of a comparatively reducedlength.

In order to allow our invention to be better understood and by way of anexample which should not be construed in a limiting sense, we will nowdescribe, reference being made to the accompanying drawings, a preferredembodiment of said invention. In said drawings:

Fig. 1 is a diagrammatic vertical sectional showing of an arrangementaccording to our invention.

Fig. 2 is a cross-section through line II-II of Fig. l, and Fig. 3 showsthe curve illustrating the concentrations per unit of surface in ahorizontal section AB of Fig. 1.

As illustrated in Figs. 1 and 2, the mixture of solid and fluid materialconveyed inside a horizontal pipe opens tangentially into the body ofthe cyclone 11 in which the flow of solid and fluid material istransformed as a consequence of centrifugal action into a generally icevertical flow which is perpendicular to the first part of the flow inthe horizontal pipe 10.

The curve showing the distribution of the concentrations of thethroughput of solid materials in the horizontal cross-section A-B of thecyclone is illustrated in Fig. 3, the concentrations being shown asordinates y, while the distances starting from a point of the wall ofthe cyclone along a horizontal diameter are shown as abscissae x. Byreason of the convergent action of the cyclone wall, the centrifugalaction increases and the concentnation peaks 12 become closer to eachother, while their intensity increases in the successive highercrosssections.

The distribution of the solid and fluid throughputs is clearly improvedat the level CD in the cyclone with reference to the usual arrangementproposed, which resorts to a vertical pipe, the height of which issubstantially equal to that of the cyclone.

However, the uniform distribution of the solid and fluid throughputsobtained precedingly may be still further improved by providing on thedown stream end of the cyclone 11 a convergent and divergent pipe member13 designed in a manner such that its convergence may be comparativelylarge while its divergence is very small. Furthermore, the divergentsection should be sufliciently long for the area of its terminaldownstream cross-section to be approximately equal to the totalutilization area.

Consequently, the device according to the invention comprises a verticalcyclone, combined with a convergent and divergent member, the convergentsection of which is very short and shows a large apical angle.

At the level of this terminal cross-section, We may arrange tuyeres thetotal cross-section of which should not be very diflerent from that ofthe said terminal crosssection, in order to cut any disturbances in theflow.

The results of tests executed by the Laboratoires DauphinoisdHydraulique show that this arrangement designed in accordance with ourinvention allows obtaining an excellent and uniform distribution of thesolid and fluid throughputs through the tuyeres arranged at thedownstream end of the main circuit.

-In practice, it has been found before and after the introduction of ourimproved apparatus a clear reduction in the dispersion of the flow andthe ratio between the minimum and maximum throughputs has dropped from1:10 to 1:1.15.

On the other hand, the application of our invention to the treatment ofliquid cast iron through a pulverulent substance with a view to removingthe sulphur has led to highly satisfactory results.

What we claim is:

1. An arrangement for homogenizing a flowing mixture of ametallurgically useful powdered material and a fluid, comprising, incombination, a frusto conically shaped hollow member vertically disposedso that the apex portion of the same is at the top, saidfrusto-conically shaped hollow member defining a free and unobstructedinner space; a substantially horizontally positioned inlet tube,tangentially entering the base of said frusto-conically shaped hollowmember; a vertical tubular extension located on the top of andcommunicating with said frustoconically shaped hollow member and havinga converging top portion terminating in an aperture having a wide apicalangle; and a divergent vertical outlet tube located on top of saidvertical tubular extension and communicating with said aperture in saidconverging top portion thereof.

2. An arrangement for homogenizing a flowing mixture of ametallurgically useful powdered material and a fluid, comprising, incombination, a frusto-conically shaped hollow member vertically disposedso that the apex portion of the same is at the top, saidfrusto-conically shaped hollow member defining a free and unobstructedinner space; a substantially horizontally positioned inlet tube,tangentially entering the base of said frusto-conically shaped hollowmember; a vertical cylindrical extension located on the top of andcommunicating with said frusto-conically shaped hollow memb r and havinga converging top portion terminating in an aperture having a wide apicalangle; and a divergent vertical outlet tube located on top of saidvertical tubular exten sion and communicating with said aperture in saidconverging top portion thereof.

3. An arrangement for homogenizing a flowing mixture of ametallurgically useful pulverulent material and a fluid, comprising, incombination, a frusto-conically shaped hollow member having its centralaxis vertically disposed so that the apex portion of the same is at thetop, said frusto-conically shaped hollow member defining a free andunobstructed inner space; a substantially horizontally positioned inlettube, tangentially entering the base of said frusto-conically shapedhollow member; a vertical tubular extension located on the top of andcommunicating with said frusto-conically shaped hollow member and havinga converging top portion terminating in an aperture having a wide apicalangle; and a divergent vertical outlet tube located on top of saidvertical tubular extension and communicating with said aperture in saidconverging top portion thereof, said vertical tubular extension and saidvertical outlet tube arranged coaxially with said frusto-conicallyshaped hollow member.

4. An arrangement for homogenizing a flowing mixture of ametallurgically useful powdered material and a fluid comprising, incombination, a frusto-conically shaped hollow member vertically disposedso that the apex portion thereof is at the top, said frusto-conicallyshaped hollow member defining a free and unobstructed inner space; asubstantially horizontally positioned inlet tube tangentially enteringthe base of said frusto-conically shaped hollow member; a verticaltubular extension coaxial with said frusto-conically shaped hollowmember, projecting from the top and communicating with the interiorthereof and having a converging top portion terminating in an aperturehaving a wide apical angle; and a divergent vertical outlet tube locatedon top of said vertical tubular extension and coaxial therewith andcommunicating with said aperture at said converging top portion thereof,said divergent vertical outlet tube being longer than said tubularextension and having an apex angle considerably smaller than said apicalangle of said aperture.

